NORTH AMERICAN NEUROPTKRA. 385 



2. — Siihnodal sertor furcate, in hind winjjs 3. 



Sul)no(lal sector not furcate in hind win<;s 4. 



3. — Anal angle of % rounded, longitudinal vein below subnodal sector does not 

 reach the margin of the wing, but ends in the wing about as far from 



anterior as from posterior margin Aiiax. 



Anal angle of % acute, above vein ends in posterior margin or near it. 



yKNclina. 

 4. — Triangle very long, superior side much more than twice as long as inferior, 



fore wing broadest beyond nodus Bft'urSP>>»<*liiia. 



Triangle shorter, superior side barely tvvife as long as inferior, fore wing 

 broadest at nodus Basia^Ncliiia. 



CORDULID^. 



1. — Hypertriagonal space free, sectors of arculus free at origin 2. 



Hypertriagonal space traversed, sectors of arculus more or less united at 



origin Maeroiuia. 



2. — No internal triangle to hind wings t'ordiilia. 



Internal triangle present Ki>itlif tra. 



LIBELLULID^. 

 1. — Triangle of wings four sided JVaiiiiotiieillis. 



Triangle of wings three sided 2. 



2. — Eyes connected in a long space, two rings on abdominal segments 2-4, bind 

 wings very broad at base, sectors of arculus pedicellate Paiitala. 



Eyes connected in a short space, but one ring on basal abdominal segments. .3 

 3. — Rings on segments 2-4. hind wings extremely broad at base Tranit'a. 



Rings on segments 2-3, none on fourth, hind wings much less broad 4. 



4. — Hind lobe of prothorax large, bilobed 5. 



Hind lobe of prothorax small entire — 9. 



o. — Sectors of arculus pedicellate 6 



Sectors of arculus not pedicellate 8. 



6. — Abdomen very slender, nearly as long as the wings; large species. 



Liepflieini!^. 



Abdomen thicker, shorter than wings; smaller species 7. 



7. — Abdomen broad, nearly equally wide throughout I?IO!i«4»llieiiiiM. 



Abdomen more slender, smaller species I>i|»lax. 



8.— Upper side of triangle as long as inner side, abdomen broad. . 1*1* I'i tlic> ill is. 



Upper side of triangle much shorter than inner side Colillieiiiis. 



9. — Sectors of arculus pedicellate 10 



Sectors of ai'culus not pedicellate Liibolliila. 



10. — Pterostigma very long, covering four or five cells Ol'tlicuiis. 



Pterostigma covering not more than three cells 11. 



11.— Hind wings distinctly broader at base than at nodus Oytlioiiiis. 



Hind wings not broader at base than at nodus TrilliciuiM. 



Order NEUKOrTKUA. 



Suborder PLANIPENNIA. 



This is divided into tvvu super-families as below : 



Hiud wings with an anal space SIALINA. 



Anal space absent MEGALOPTERA 



TEANS. AM. ENT. SOC. XIX. DECEMBER, 1892. 



